by Trent A. Fisher and Werner Lemberg - The GNU Operating System

Chapter 2: Invoking groff 15
2.6 Invocation Examples
This section lists several common uses of groff and the corresponding command
lines.
groff file
This command processes ‘file’ without a macro package or a preprocessor.
The output device is the default, ‘ps’, and the output is sent to stdout.
groff -t -mandoc -Tascii file | less
This is basically what a call to the man program does. gtroff processes the
manual page ‘file’ with the ‘mandoc’ macro file (which in turn either calls
the ‘man’ or the ‘mdoc’ macro package), using the tbl preprocessor and the
ASCII output device. Finally, the less pager displays the result.
groff -X -m me file
Preview ‘file’ with gxditview, using the ‘me’ macro package. Since no ‘-T’
option is specified, use the default device (‘ps’). Note that you can either say
‘-m me’ or ‘-me’; the latter is an anachronism from the early days of UNIX. 1
groff -man -rD1 -z file
Check ‘file’ with the ‘man’ macro package, forcing double-sided printing –
don’t produce any output.
2.6.1 grog
grog reads files, guesses which of the groff preprocessors and/or macro
packages are required for formatting them, and prints the groff command
including those options on the standard output. It generates one or more
of the options ‘-e’, ‘-man’, ‘-me’, ‘-mm’, ‘-mom’, ‘-ms’, ‘-mdoc’, ‘-mdoc-old’,
‘-p’, ‘-R’, ‘-g’, ‘-G’, ‘-s’, and ‘-t’.
A special file name ‘-’ refers to the standard input. Specifying no files
also means to read the standard input. Any specified options are included
in the printed command. No space is allowed between options and their
arguments. The only options recognized are ‘-C’ (which is also passed on)
to enable compatibility mode, and ‘-v’ to print the version number and exit.
For example,
grog -Tdvi paper.ms
guesses the appropriate command to print ‘paper.ms’ and then prints it to
the command line after adding the ‘-Tdvi’ option. For direct execution,
enclose the call to grog in backquotes at the UNIX shell prompt:
‘grog -Tdvi paper.ms‘ > paper.dvi
As seen in the example, it is still necessary to redirect the output to something
meaningful (i.e. either a file or a pager program like less).
1 The same is true for the other main macro packages that come with groff: ‘man’,
‘mdoc’, ‘ms’, ‘mm’, and ‘mandoc’. This won’t work in general; for example, to load
‘trace.tmac’, either ‘-mtrace’ or ‘-m trace’ must be used.